It has often been proposed to use stacked arrays of transmissive cells, such as colored LCD panels, to yield color displays. However, such efforts have heretofore not been satisfactory. In some realizations of the theory, the resulting display contrast is unacceptable. In others, the display brightness suffers. In still others, the gamut of possible colors is limited. In many, parallax limits the viewing angle.
It is an object of the present invention to overcome these disadvantages to provide a high contrast, high brightness color display that can be satisfactorily viewed over a wide viewing angle.
In accordance with one embodiment of the present invention, a display system is formed by stacking three birefringent LCD panels that are tuned to different subtractive primary colors (i.e. yellow, cyan and magenta). Interposed between the panels, and sandwiched about the stack, are polarizers. At least some of the polarizers are colored to improve the resulting brightness. In some embodiments, the assembly is illuminated by a collimated light source and the resulting image is focused onto a projection screen for viewing. In other embodiments, arrays of lens elements on the front and rear surfaces of the assembly permit direct viewing of the image without parallax effects.
The foregoing and additional objects, features and advantages of the present invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.